begin refactor of proxy engine

proxychain/rqm/request_wayback_machine.go

@@ -0,0 +1,22 @@
+package rqm // ReQuestModifier
+
+import (
+	"ladder/proxychain"
+	"net/url"
+)
+
+const waybackUrl string = "https://web.archive.org/web/"
+
+// RequestWaybackMachine modifies a ProxyChain's URL to request the wayback machine (archive.org) version.
+func RequestWaybackMachine() proxychain.RequestModification {
+	return func(px *proxychain.ProxyChain) error {
+		px.Request.URL.RawQuery = ""
+		newURLString := waybackUrl + px.Request.URL.String()
+		newURL, err := url.Parse(newURLString)
+		if err != nil {
+			return err
+		}
+		px.Request.URL = newURL
+		return nil
+	}
+}